1. Technical Field of the Invention
This invention broadly relates to locking devices. The invention further relates to locking devices useful to physically restrain the movement by an individual of his or her arms and/or legs. This invention more particularly relates to mechanical restraining devices referred to in the art as xe2x80x9chandcuffs.xe2x80x9d This invention specifically relates to an operating mechanism and to a locking mechanism for a handcuff.
2. Description of the Prior Art and Problems Solved
It is known in the art that a handcuff is an apparatus, usually made of metal, which, when employed, is ordinarily placed around the wrist or ankle of an individual. The apparatus, can be, and usually is, directly connected to another such device by a bridge, such as a chain, a link, or a bar, to thereby form a combination of such devices. The combination is referred to in the art and herein as xe2x80x9chandcuffsxe2x80x9d or as a xe2x80x9cset of handcuffs.xe2x80x9d
It is also known in the art to place handcuffs upon an individual to render such individual physically ineffective or powerless. Accordingly, handcuffs can be employed, for example, in the field of law enforcement for the purpose of physically restraining an individual from escape and/or to prevent such restrained individual from injuring himself and/or some other person, such as a police officer. It is apparent, then, that a handcuff, or handcuffs, which can be opened and removed by the person being restrained, or by any other unauthorized person, either by force or by device, utterly defeats the purpose of the handcuffs.
As known in the art, a handcuff contains mechanisms which function to permit the apparatus to open and close and also function to prevent the apparatus from opening. The first function is referred to herein as the xe2x80x9coperating mechanism.xe2x80x9d The second function is referred to herein as the xe2x80x9clocking mechanism.xe2x80x9d
An example of a handcuff known in the art which includes an operating and a locking mechanism can be an apparatus comprised of a combination of at least two, and sometimes three, planar, substantially parallel, plates and a movable arm. The plates and movable arm cooperate to produce a ring defined herein as a xe2x80x9crestraining spacexe2x80x9d which can be opened and closed. It is to be understood that the wrist or ankle of the individual to be restrained is placed and confined in the closed restraining space.
The combination of plates is a sandwich structure comprised of two, aligned, exterior plates which cooperate to form a stationary arm and an enclosed interior space. The enclosed interior space is, for convenience, referred to herein as the xe2x80x9cmachinery space.xe2x80x9d The machinery space can sometimes be further defined by cavities formed in a third plate positioned between the two exterior plates. The third plate thus separates the exterior plates and provides a cavity or cavities in which the operating and locking mechanisms are positioned.
Each exterior plate is ordinarily a unitary body comprised of a first section, referred to herein as a xe2x80x9ccheek plate,xe2x80x9d and a second section, referred to herein as a xe2x80x9cplate arm.xe2x80x9d The cheek plates serve as the top and bottom covers of the machinery space and as a base to support the operating and locking mechanisms positioned in the machinery space. The plate arms combine to form the stationary arm. The third plate, when employed, is positioned between the cheek plates and can be considered to be a part of the housing for mechanisms positioned in the machinery space.
Each plate arm, which extends beyond the cheek plate to form one side of the stationary arm, is a rigid, curvilinear, i.e., a xe2x80x9cC-shaped,xe2x80x9d member which terminates at an end adapted for hinged attachment to the movable arm. The stationary arm, which as stated, is formed by the combination of the aligned, curvilinear, plate arms, is referred to as such to distinguish the combination of plate arms from the movable arm of the handcuff. The combination of the terminal ends of each plate arm is referred to as the hinge end of the stationary arm.
The movable arm of a handcuff, which has been variously referred to as a curved locking arm as a swing arm, is also a rigid, curvilinear member having a pivot end and a free end. The pivot end of the swing arm is positioned between the terminal ends of each plate arm and is rotably connected to the hinge end of the stationary arm. The free end of the swing arm is equipped with teeth adapted to engage, that is, contact and intermesh with, opposing teeth mounted within the machinery space.
Accordingly, in operation, the pivot end of the swing arm and the hinge end of the stationary arm cooperate to permit the free end of the swing arm to rotate into at least a portion of the machinery space wherein the teeth on the free end of the swing arm engage teeth mounted within the machinery space to thereby form and close the restraining space. In handcuffs known in the prior art the restraining space is opened by causing the respective teeth to disengage followed by rotating the swing arm out of the machinery space.
From the above description it is evident that a handcuff functionally comprises a restraining space and a machinery space. The prior art of particular interest herein is the specific operating and locking mechanisms employed in the machinery space.
The operating mechanism of a prior art handcuff is embodied in a substantially linear member enclosed in the machinery space which features a plurality of teeth mounted on one side thereof which are adapted to engage teeth on the swing arm. The prior art operating mechanism is hinged at one end and biased to urge the teeth on the member into engagement with the teeth on the swing arm. The mechanism can be thus characterized as a hinged pawl situated within the machinery space of the handcuff. The swing arm must enter the machinery space to close the restraining space. Accordingly, the swing arm is rotated into the machinery space with force sufficient to overcome the resistance of the biasing source to cause the pawl to rotate about the hinge. The result of this action is to raise the teeth on the pawl out of engagement with the teeth on the swing arm. The operating mechanism of the prior art thus employs a reciprocating action wherein the teeth on the pawl and the teeth on the swing arm are contiually alternating between an engaged and a disengaged condition as the swing arm is rotated into the machinery space.
A prior art handcuff features a first operating position and a second operating position. The first operating position is referred to as the xe2x80x9cready-to-lockxe2x80x9d position. In this position, the swing arm is permitted to swing inwardly into the machinery space of the handcuff to close and reduce the area of the restraining space, to thereby tighten the restraint around the wrist or ankle of an individual, but the handcuff is not permitted to be loosened or opened because the teeth of the pawl are designed to permit inward, but not outward, movement of the teeth on the swing arm. It is believed that the shape of the teeth of the pawl and the teeth of the swing arm combine to prevent the swing arm from rotating out of the machinery space of the handcuff.
The second operating position, referred to as the xe2x80x9cdouble lockedxe2x80x9d or secondary locking position, employs, as the locking mechanism, a movable physical barrier, such as a rod or a bar, positioned within the machinery space of the handcuff to prevent the pawl from performing the mentioned reciprocating action and, therefor, prevents the swing arm from rotating around the hinge end of the stationary arm. In the second operating position, the swing arm cannot be moved in either direction (i.e., inwardly into or outwardly out of the machinery space of the handcuff), because the pawl teeth are caused to remain in continuous contact with the teeth of the swing arm by the locking mechanism to prevent any movement of the swing arm. In this regard, the reciprocating movement of the pawl to disengage the pawl teeth is prevented by the mentioned rod or bar positioned between the reciprocating, i.e., free, end of the pawl and the inner surfaces of the cheek plates of the handcuff.
As mentioned, prior art handcuffs, and similar such restraints, employ a combination locking and operating mechanism featuring a swing arm having ratchet teeth in operable combination with the teeth of a pawl. These mechanisms are not secure because they can be opened by force, for example by jimmying and jarring. There is, thus, a need for a locking and operating mechanism which resists being unlocked by leverage, impact and rotational forces which employ tools, such as lock picks and shims.
It is well known that handcuffs and restraints employing the prior art ratchet and pawl mechanism can be forcibly opened by use of a thin flat item, such as a small metal ruler or by a plastic credit card. In this regard, and as previously mentioned, the prior art ratchet and pawl operating and locking mechanism, in the very act of contacting and intermeshing the teeth of the pawl with the teeth of the swing arm, inherently involves the teeth on the pawl and the teeth on the swing arm continually alternating between an engaged and a disengaged condition. This inherent action can be exploited in a technique called xe2x80x9cjimmying,xe2x80x9d wherein a shim, such as a thin flat item, is forced between the teeth of the swing arm and the teeth of the pawl to overcome the biasing source and raise the pawl by an amount sufficient to interrupt contact between the teeth of the pawl and the ratchet teeth to enable the outward movement of the swing arm to thereby open the restraining space.
It is further known that the above described prior art ratchet and pawl handcuffs and restraining devices employ a simple rod or bar, which, when properly positioned, prevents the pawl from being raised by a shim. Positioning the rod or bar can be accomplished by inserting the pin end of the handcuff key into a small hole in the side of the handcuff to move the bar. The locking mechanism can be defeated by striking the handcuff on a solid object, such as a rock or pavement, to jar the bar out of position. Once the secondary locking mechanism has been jarred out of position, the handcuffs or restraints can then be jimmied as described above.
A prior art handcuff key is little more than a piece of metal which, upon rotation within the key way, positions a cam to cause or prevent vertical movement of the pawl. The rotation of the key about its longitudinal axis requires so little torque to move the cam that an operable key can be formed from a paper clip.
Furthermore, in a technique called xe2x80x9cpicking,xe2x80x9d a paper clip, or other bendable yet sturdy element, can be modified and used along with other small pieces of wire to perform the same function as the key.
In view of the problems involving the operating and locking mechanisms of handcuffs of the prior art, it is an object of this invention to provide a handcuff having an operating mechanism which is at all times in full contact and intermeshed with teeth on the swing arm when the handcuff is being either opened or closed. Another object of this invention is to provide a handcuff having a locking mechanism which can permit or prevent movement of the operating mechanism. These and other objects, advantages and features provided by this invention will become apparent to those persons skilled in the art from a consideration of the following description and drawings which describe the apparatus of this invention and the manner and process of making and using the same.
This invention provides an apparatus useful as a handcuff. The apparatus is comprised of a housing having an operating and a locking mechanism enclosed therein, wherein the housing, as shown in FIG. 1, is comprised of at least two, substantially identically shaped, opposed, substantially parallel, plates, 6 and 7, and a swing arm, 22. Each plate is a unitary body having an inside surface, an outside surface, an arm side, A, and an open side, B. Each plate, such as plate 6, for convenience of reference herein, is divided into a first section, 6a, referred to as a xe2x80x9ccheek plate,xe2x80x9d and a second section, 6b, referred to as a xe2x80x9cplate arm.xe2x80x9d A plate arm is a narrow, elongated, curvilinear part of the plate which extends in an arc from the arm side of the plate to a terminal end on the open side of the plate. The plates are spaced apart to provide a machinery space between the opposed inside surfaces of each cheek plate and a curvilinear stationary arm defined by the spaced, opposed plate arms. The space between the terminal ends of the plate arms is referred to as the hinge end of the stationary arm.
The swing arm, like the stationary arm, is also a narrow, elongated curvilinear body having a pivot end and a free end. The pivot end of the swing arm is positioned between the terminal ends of the plate arms and rotatably connected to the hinge end of the stationary arm. The swing arm extends in an arc toward the open side of each plate from the hinge end of the stationary arm to the free end of the swing arm. The free end of the swing arm is equipped with teeth adapted to engage, that is, contact and intermesh with, opposing teeth mounted within the machinery space.
The swing arm, the stationary arm, and the inner edges of the opposed cheek plates cooperate to form the restraining space of the handcuff when the free end of the swing arm is rotated into and engaged with teeth mounted in the machinery space.
The operating mechanism of this invention is housed in the machinery space between the opposed cheek plates. In one embodiment, the operating mechanism of this invention can be a toothed wheel, that is, a gear, whose teeth engage the teeth mounted on the swing arm. In another embodiment, the operating mechanism of this invention can be comprised of two gears, each of whose teeth can simultaneously engage the teeth mounted on the swing arm. In still another embodiment, the operating mechanism of this invention, as shown in FIGS. 2-4, can be comprised of an array of three intermeshing gears having two gears, referred to herein as xe2x80x9cworking gears,xe2x80x9d whose teeth can simultaneously engage the teeth mounted on the swing arm, and a third gear, referred to herein as an xe2x80x9cidler gear,xe2x80x9d whose teeth are continually and simultaneously engaged with the teeth on the two working gears. When the handcuff is being opened or closed, that is, when the restraining space is being opened or closed, teeth mounted on the swing arm are always in contact with teeth on at least one of the working gears. Thus, gear teeth engage teeth of the swing arm when the swing arm is in the closed position and not moving, as shown in FIG. 4, when the swing arm is being rotated toward the open side of the plates to place the handcuff into the closed position, as shown in FIG. 3, and when the swing arm is being rotated away from the open side of the plates to place the handcuff in an open position, as shown in FIG. 2.
Any working gear of the operating mechanism having teeth engaged, that is, in contact and intermeshed, with teeth on the swing arm must rotate to enable any rotational movement of the swing arm. This invention, accordingly, further provides a multi-function locking mechanism which controls the rotation of the gears. The locking mechanism of this invention is housed in the machinery space between the opposed cheek plates in a location separate from the operating mechanism.
In a first locking position, shown in FIG. 3, referred to herein as the xe2x80x9cclosing position,xe2x80x9d the locking mechanism is positioned to permit rotation of the gears in one direction to thereby permit closing rotation of the swing arm, and to prevent rotation of the gears in the opposite direction to thereby prevent opening rotation of the swing arm. In a second locking position, shown in FIG. 4, referred to herein as the xe2x80x9clocked position,xe2x80x9d the locking mechanism is positioned to prevent any rotation of the gears in any direction to thereby prevent any rotation of the swing arm in any direction. In a third locking position, shown in FIG. 2, referred to herein as the xe2x80x9cfree position,xe2x80x9d the locking mechanism is positioned to permit rotation of the gears in any direction to thereby permit rotation of the swing arm in any direction.
Having, thus, generally alluded to the apparatus as a whole, it will be appreciated that the operating mechanism of this invention is broadly comprised of a first working gear and a swing arm. In this regard, the first working gear is rotatably mounted on a first gear axle which is perpendicularly attached to a planar base, and the swing arm is rotatably mounted on a swing arm axle which is also perpendicularly attached to the planar base a first fixed distance from the first gear axle.
The first working gear is a wheel having a first radius. Teeth are mounted on the outer edge of the wheel which rotates around the first gear axle in a plane parallel to the plane of the planar base.
The swing arm is a curvilinear member having a first end and a second end. Teeth are mounted on the outer edge of the first end. The distance from the outer edge of the first end of the swing arm to the swing arm axle is referred to as the second radius. The swing arm rotates around the swing arm axle in a plane parallel to the planar base.
The mentioned first fixed distance is substantially equal to the sum of the lengths of the first radius and the second radius. Accordingly, the teeth on the first working gear and the teeth on the swing arm contact and intermesh each with the other upon rotation of the first working gear around the first gear axle and rotation of the swing arm around the swing arm axle. The teeth on the first working gear and the teeth on the swing arm are thus adapted to intermesh upon contact.
The operating mechanism of this invention can further include a control pin comprising a linear rod slidably mounted on, and parallel to, the fixed planar base in a position opposed to the first working gear and preferably perpendicular to the first axle. The rod has a proximal end, a distal end and a biasing means, such as spring, abutting the distal end of the rod to urge the proximal end of the rod into contact with the teeth on the first working gear. The proximal end of the rod is adapted to contact the teeth on the first working gear to permit rotation of the first working gear around the first axle in one rotational direction while preventing rotation of the first working gear around the first axle in the opposite rotational direction.
The operating mechanism of this invention can be further controlled by a locking mechanism which converts rotational motion to linear motion. The locking mechanism is thus comprised of a cam in operable combination with a cam follower, referred to herein as a cam lever which is perpendicularly and rigidly attached to the mentioned linear rod of the control pin at a point intermediate the proximal end and the distal end of the linear rod.
The cam is a plate in the shape of a yoke having a hole in one end, referred to as the axle end, and a forked end linearly spaced apart from the axle end. The cam is, accordingly, referred to herein as a yoke. The axle end of the yoke is closed and rotatably mounted on a yoke axle. The forked end of the yoke is open having a first leg on one side of the opening and a second leg on the opposite side of the opening side wherein the second leg is spaced apart from and, preferably, parallel to the first leg.
The yoke axle is perpendicularly fixed to the planar base. The axle end of the yoke is rotably mounted on the yoke axle so that the cam lever on the control pin is situated between the first leg and the second leg of the forked end of the yoke. The yoke rotates around the yoke axle in a plane parallel to the planar base.
As seen in FIG. 2, rotation of the yoke around the yoke axle in one rotational direction causes contact between the cam lever and the inside surface of the first leg to thereby linearly urge the rod against the biasing means at the distal end of the rod. As seen in FIG. 4, rotation of the yoke around the yoke axle in the opposite rotational direction causes contact between the cam lever and the inside surface of the second leg to thereby linearly urge the proximal end of the rod against the teeth of the first working gear.
The operating mechanism of this invention can be further comprised of a second gear axle and a second working gear wherein the second gear axle is perpendicularly attached to and positioned on the planar base a second fixed distance from the first gear axle and a third fixed distance from the swing arm axle. The second working gear is rotatably mounted on the second gear axle to enable the second working gear to rotate around the second gear axle in a plane parallel to the plane of the base. The second working gear is a wheel having a third radius and teeth mounted on the outer edge thereof.
The third fixed distance is substantially equal to the sum of the lengths of the second radius and the third radius whereby the teeth on the second working gear and the teeth on the swing arm are in contact and intermesh each with the other upon rotation of the second working gear around the second gear axle and rotation of the swing arm around the swing arm axle. The teeth on the second working gear and the teeth on the swing arm are thus adapted to intermesh upon contact. In a preferred embodiment, the radius of the second working gear, that is, the third radius, is equal to the radius of the first working gear, that is, the first radius.
The operating mechanism of this invention can be further comprised of an idler gear, a wheel having a fourth radius and teeth mounted on the outer edge the wheel, wherein the teeth on the idler gear and the teeth on the first working gear are in contact each with the other. The teeth on the idler gear and the teeth on the first working gear are adapted to intermesh upon contact.
The idler gear is rotatably mounted on an idler gear axle which is perpendicularly attached to, and positioned on, the planar base a fourth fixed distance from the first gear axle, a fifth fixed distance from the second gear axle and a sixth fixed distance from the swing arm axle. The idler gear rotates around the idler gear axle in a plane parallel to the plane of the planar base.
It is preferred that the teeth on the idler gear and the teeth on the second working gear also contact each other. Accordingly, the teeth on the idler gear and the teeth on the second working gear are adapted to intermesh upon contact and the third radius is equal to the first radius and the third fixed distance is equal to the first fixed distance. It is also preferred that the fourth radius is equal to the first radius.
The locking mechanism of this invention can be, and is preferably, further comprised of a means for rotating the yoke on the yoke axle and detent means for maintaining the position of the yoke with respect to the cam lever in either the previously mentioned closing position or the previously mentioned locked position.
It is believed that the specific locations of the operating and locking mechanisms of this invention within separate machinery spaces as well as structural features of the swing arm and the machinery spaces, serve to prevent the insertion of any object, such as a shim, between the swing arm teeth and the gear teeth and/or between the locking mechanism and the gear teeth. Even if any object is inserted between any of the various teeth and mechanisms, then, It is further believed, that the shim will become wedged in the teeth and or gears which will operate to prevent any rotation of the gears and thus prevent any rotation of the swing arm.
It is clear that the operating mechanism of the present invention replaces the pawl of the prior art with a gear or gears, which are constantly, and fully engaged with the teeth of the swing arm. The operating gears can not be jimmied open by the insertion of a metal or plastic shim. Additionally, the locking mechanism utilizes a yoke that is positioned and formed to make it difficult to pick by anyone.